The invention relates to a hybrid module for a drive train.
The automotive sector is increasingly trending toward hybrid vehicles, which include a further drive, such as an electric drive, for example, in addition to a conventional internal combustion engine. The two drives are typically coupled to a drive train via what is known as a hybrid module, so that the torque generated by the drives can be transmitted to a shared driven axle of the hybrid vehicle. The two drives have different optimal operating points, for which reason at least the internal combustion engine is decoupled from the drive train in certain operating ranges. This is typically carried out by way of a separating clutch.
For comfort reasons, it is preferred for the vibrations generated by the internal combustion engine to be damped to an extent as great as possible. A damping system is thus provided for vibration damping. All these components require installation space; said space, however, is only available to a limited extent because the body of a hybrid vehicle is no different from that of a conventional vehicle. The limited available installation space accordingly affects the dimensions of the further drive, causing the power of the same to be limited.
It is one object of the invention to create a hybrid module that allows an internal combustion engine and a further drive to be coupled to a drive train in minimized space.
This and other objects of the invention are achieved by a hybrid module for a drive train, comprising a drive, in particular an electric drive, a first coupling section for coupling the hybrid module to a transmission, and a second coupling section for coupling the hybrid module to an internal combustion engine, wherein the second coupling section comprises a shifting system having at least two shifting elements, which can assume a starting position and a shifting position.
One aspect of the invention is to couple the hybrid module to the internal combustion engine via a shifting system that requires less installation space than the customarily used separating clutch. The space that is saved can be available for the further drive, for example, whereby the same can be designed to be more powerful. The hybrid module furthermore creates installation space for a friction starting clutch connected upstream of the actual transmission set, or for an upstream integrated starting element. Said starting element can be used for starting with slippage, which is to say a rotational speed that is greater than the output rotational speed, which is zero, is generated via the internal combustion engine and/or the electric motor. The internal combustion engine can be started via the hybrid electric motor or a separate starter device. The torque converter used in drive trains of automatic transmissions can be dispensed with.
One aspect of the invention provides for a damping system for torsional vibrations, which comprises in particular at least one dual mass flywheel and/or a centrifugal pendulum. The damping system can effectively damp the vibrations originating from the internal combustion engine, so that the drive train is subjected to uneven running characteristics to a lesser degree. Due to the configuration of the hybrid module according to the invention, and in particular of the second coupling section, the damping system can have a more comprehensive design, whereby the vibrations that occur can be suppressed even better.
According to a further aspect of the invention, the shifting system comprises an actuator, which actuates at least one of the shifting elements, and in particular actuates the same electrohydraulically or electromechanically. The shifting system comprises an electromechanical or electrohydraulic shifting actuator, which can be used to actuate at least one of the shifting elements autonomously with respect to the main transmission, which is to say independently of the same.
In particular, the shifting elements are coupled in a chamber accommodating a lubricant. The shifting elements are thus lubricated, whereby friction-induced signs of wear over the operating time of the hybrid module are mitigated. The chamber can be designed such that sufficient lubricant is present to lubricate the shifting elements over the entire service lives thereof. Possible lubricants are in particular oil or grease.
A further aspect of the invention provides for the shifting elements to be designed in a form-locked manner with respect to each other, and in particular as claw elements. High forces can thus be transmitted in the shifting position since the shifting elements bear on one another across a large surface area. This reduces the signs of wear on the shifting elements.
Furthermore, the shifting elements can have a substantially cylindrical design, wherein, in the shifting position, the one shifting element at least partially surrounds the other shifting element peripherally. In this way, it is ensured that the two shifting elements cooperate with each other across a large effective surface, whereby the coupling can be achieved quickly and torque transmission is accordingly favorable.
In particular, the shifting elements can have a conical design, so that they nestle more gently inside one another during the transition from the starting position into the shifting position.
A further aspect of the invention provides for the shifting elements to be provided with friction surfaces. Friction torque is generated via the friction surfaces, which improves coupling and torque transmission. The friction surfaces can also be used to synchronize the shifting operation.
In particular, the shifting system comprises at least one spring element, which is provided between one of the shifting elements and the damping system. The spring element ensures that the hybrid module couples the drive train to one of the two drives when the actuator fails. This may in particular involve the internal combustion engine, which is coupled to the drive train when the electronics system of the hybrid vehicle fails.
The shifting system is normally closed by way of the spring element, which is to say it is in the normally closed position.
According to a further aspect of the invention, the coupling sections are designed as part of a keyed joint. The hybrid module can thus be easily coupled to a transmission and to the internal combustion engine. In this way, the hybrid module in particular has a modular design and can be used for different drive trains.
Furthermore, shiftable freewheeling may be provided on the hybrid module, so that the internal combustion engine and the further drive can be decoupled from the driven assembly.
Further advantages and properties of the invention will be apparent from the following description and the FIGURE being referenced.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawing.